Arctic-subarctic coastal hazards and morphodynamics (AsCHMor)

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Coastal storms shape coastlines at various scales and affect millions of people annually. Although widely studied in southern countries, storm impacts are still poorly understood in the Arctic because high-frequency measurements are hardly feasible on remote coasts. Coastal changes are nevertheless affecting Inuit communities, and are enhanced by permafrost thaw and sea ice reduction. The latter further contributes to increased wave heights. Extreme coastal events in arctic and subarctic regions are presumably caused by combined high water levels and waves, either under open or ice-infested waters. Cryogenic processes and hazards involve sea ice freeze/break-up, freeze-thaw cycles, and ice push ridges. Varying isostatic adjustments throughout the Arctic also result in contrasting sea-level variations that blur the impacts of coastal erosion and flooding. We hypothesize that frozen sediments also controls coastal overwash processes, and this is a primary concern for coastal management. On frozen coasts, it is therefore not trivial to predict coastal evolution in the long term. The objective of the Arctic-subarctic coastal hazards and morphodynamics (AsCHMor) research program is to significantly improve our understanding of coastal morphodynamics in the arctic-subarctic region and to enhance our capacity to simulate and predict future coastal behaviors under the impacts of climate change and increasing human pressure on the coast. The program targets two components of coastal hazards rarely explored in the Arctic. First, AsCHMor will be implemented (i) to better understand the complex interactions between beach sediment permeability and pore-ice saturation in the swash zone during energetic storms in northern Canadian communities. (ii) The second component integrates the exploration and application of empirical/numerical models of coastal total water levels in ice-infested waters at both regional and local scales to improve our risk management capacity. AsCHMor will be implemented throughout an iterative process using numerous observational, modeling, and technological development. Eleven HQP (5 B.Sc., 4 M.Sc., 2 Ph.D.) will perform field works on subarctic and High Arctic coastal communities (St. Lawrence Estuary, Hudson Bay, Jones Sound). Capitalizing on my previous works, a novel shore-based video network designed with national and international collaborators will be deployed. This proposal is unique and necessary to improve knowledge gaps in Arctic coastal dynamics and hazards. Its implementation will benefit northern communities by providing new predictive tools on fast-onset coastal disasters situations. It will increase autonomy in community decision-making through scientific research and monitoring. The long-term goal of AsHCMor is to strengthen Canada's forecasting services and early warnings in the north and to provide efficient information on time for evacuation and adaptation strategies in northern communities.